Six ways of managing things that prevent access to the cool, six which provide access to the cool.
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Index to available translations: AN 6.85
There is here a way of looking at the mind which frees one from the tendency to think that it must be just one way or another.
In this sutta we can see that it is more like a horse that needs to be trained to do what we want, or a car that we must learn to drive properly.
When you drop that piece of litter as you are walking along, the mind tells you instantly to pick it up. If you ignore that, you are not 'giving heed to the mind when it ought to be given heed to.
When you slow down and come to a halt confronting some problem and give up and go on to the next thing, you are not exerting the mind when it ought to be exerted.
When you see you are getting silly, going off in a wrong direction, the mind tells you right then that you should stop. If you do not heed the mind then and stop, you are not 'checking the mind when it ought to be checked.
When you are getting discouraged and feel you are making no progress, and do not reflect on the progress that you have already made and on the magical way the Dhamma has of little-by-little inevitably irresistably eating away at the dullness of the mind, you are not gladdening the mind when it needs to be gladdened.
And the converses: when you do, you are.
Pay attention to that voice! It is not just that dreary moraliztic preacher known as the conscience. It is con-science: co-knower of your every action, and always has good advice if you listen when it has good advice and put a check on it when it is giving bad advice. (As long as there is the notion of self, it flips back and forth.)